Manufacture of paper and like bags, envelopes, and the like



Aug. 20, 1940. 2,212,469

fmnumcruns OF PAPER AND LIKE was, ENVELOPES, AND THE LIKE 6. w. FRENCH Filed May 9, 1939 Inventor 80200! N Fen/cu by f g I f Attorney:

PatentedAug. 20, 1940' UNITED STATES MANUFACTURE OF PAPER AND LIKE BAGS, ENVELOPES, AND THE LIKE Gordon William French, Bristol, England, assigner to Beasley, French and Company Limited, Bristol, England Application May 9, 1939, Serial No. 272,590 In Great Britain July 12, 1938 7 Claims.

This invention relates to the manufacture of or envelopes of paper or like material to be made upon high speed bag making machines in an economical manner'and without any waste of material. l

According to this invention the width of the sheet material appropriate to one side of the ultimate bags is weakened or perforated by suitable means before entering the breaking or cutting off stage, the remainder of the width of the sheet material being severed or broken-by a suitable cutter or breaker operating substantially contemporaneously with the application of tension to the. tubular sheet material sufficient to break the weakened or perforated side of the tubular sheet material along the perforated or weakened line.

In carrying one form of this invention into practice the sheet material before being folded into tubular form is fed between means for perforating it at regular intervals transversely for a portion of its width so predetermined that the perforated part is contained in one side of the tubular sheet material when the material is folded into tubular form,-the other side not being perforated. After passing the folding stage the tubular sheet material is drawn by suitable rollers along a former plate, and operating close to the exit edge of the former plate is a transversely disposed cutting .blade adapted to sever the imperforated side of the material and a dummy or presser bar may operate against the perforated side of the material, the blade and bar being arranged to operate against the tubular sheet'material practically simultaneously and with their operative or free edges travelling close to each other. Means is provided to momentarily increase the tension on the sheet material when the cutting blade and the dummy or presser bar engage the sheet material, and this momentarily increased tension in conjunction with'the pressure applied by the dummy or presser bar breaks the perforated side of the tubular sheet material,

the cutting blade shearing the other side. In suitable means for this purpose the tubular sheet material is drawn from the former plate by a pair of rollers, one of which is slightly increased in radius for a short portion of its periphery, which portion engages'the tubular sheet material immediately in advance of and during the cutting-off stage.

The perforating of the sheet material is preferably efiected before folding it into tubular form, the perforating may however, be effected when the sheet material is in tubular form, e. g. when passing over the former plate.

If desired the web may be creased at intervals corresponding to the position at which the flap 16 of each envelope is intended to fold so as to facilitate the folding over of the flap. When the: envelope is intended to be sealed, suitable adhesive may be applied to the areas forming the appropriate parts of the flaps whilst the mag0 terial is in web form.

In order that this invention may be clearly understood and readily carried into effect a sheet of drawings is appended hereto illustrating an embodiment thereof, and wherein:

Fig. 1 is a plan view showing the manner of locating the. perforations in the sheet material when producing bags or envelopes in which the flaps and recesses occur in the seamed sides of thebags or envelopes.

Fig. 215 a. diagrammatic side elevation view showing the various stages of the relevant operations.-

Fig. 3 is a plan view showing a suitable form of perforating roller.

Fig. 4 is a sectional end elevation of Fig. 3.

Fig. 5 is 'a'plan view of a bag or envelope severed section with the flap and corresponding recess at opposite ends produced across the seamed side of the bag or envelope, and

Fig. 6 is a plan view of a bag or envelope severed section with the flap and correspondingrecess at opposite ends produced across the unseamed side of the bag or envelope.

Referring to the drawing the arrangement 45 shown in Fig. 2 is such as to produce in the sheet material at regular intervals substantially transverse lines of perforations '-I (see Fig. 1) in the sheet material 2, these substantially transverse lines of perforations'extending across the paper 50 the distance corresponding to the width of one. side of the tubular sheet material. It is preferred to perforate the sheet material on these lines I before folding it into tubular form, and for this "purpose as shown in Fig. 2 the sheet material before reaching the folding stage 3 is passed between a rubber covered roller 4 and a roller 5 carrying perforated blades 6. When the sheet material is folded into tubular form and drawn by rollers l and 8 over the customary former plate 9, the upper side contains the substantially transverse lines of perforations I, the upper side being the seamed side.

Operating against the lower side of the tubular sheet material close to the exit edge of the former plate 9 is a cutting blade l0, e. g. a blade projecting at the desired angle from a rotary cylinder II, this blade cutting through the lower layer of material as it leaves the former plate. Operating against the upper side of the tubular sheet material so as to engage the upper side practically simultaneously with the engagement of the lower side by the cutting blade 10 is a dummy or presser bar l2 having a blunt free edge suitably shaped so as not to impede the cutting action of the blade l0 and yet applying pressure or slight distortion to the upper side of the tubular sheet material to break the material along the appropriate perforated line I. sure a simultaneous positive cutting'operation of the lower side and a breaking action along the perforated line of the upper side, simultaneously with the engagement of the sheet material by the cutting blade l0 and the bar [2 the material is placed in momentarily increased tension as it is drawn off the former plate, this being effected by forming on one of a pair of rollers l3 and H drawing the sheet material across-the severing stage an increased radius portion l5 which engages the tubular sheet material immediately be-- fore and during the severing stage. v

The means for perforating the sheet material is preferably that shown in Figs. 3 and 4, in which a thin blade lliwith a toothed perforating edge I1 is gripped between a block l8 and a plate l9 detachably fitted in a channel in the roller 5 and shaped to present outer parts curved in continuity with the periphery of the roller 5. Studs 23 passed through the adjacent part of the roller and the plate 19 and block 58 effect the requisite clamping action. In the majority of cases the tubular sheet material is severed to afford flaps at the ends of each severed section, one of which flaps is folded over and sealed against one side of the bag section, and for this purpose the block I 8 is provided with radiused or arcuate corners Illa, or can be bowed its full length on the side engaging the blade It, the plate l9 being correspondingly shaped.

The perforating of the sheet material before reaching the folding stage is advantageous when producing bags or envelopes in which end flaps 2| (see Fig. 5) and correspondingly shaped end recess 22 are formed in the side of the tubular material containing the seam 23 formed by overlapping and adhering together the longitudinal edges of the sheet material. If however, the flaps 2| and recesses 22 are to be formed across the non-seamed side, the perforating of such side can be effected by a'perforating tool acting against one side of the former plate 9, or an additional plate located to receive the material in tubular form, such plate if desired having a pluthe perforating tool or being lined with rubber on the appropriate side. The plate is adapted to move in unison with the tool during perforation.

The foregoing described method of perforating and cutting the opposite sides of the tubular material has the advantage of producing bag or To en envelope sections in which the end flaps 2| are provided ready for folding against the envelope or bag, and the recessed ends are easily sealed by folding each tubular section transversely on the line 24 and adhering the'non-recessed short end part against the outer face of the side of the bag. section containing the flap 2 I. By this means there is no waste of material and although the predominating area of the sealed part contains only a single thickness of folded over non-recessed side part of the bag or envelope, the corners are thicker and stronger as they contain the lateral marginal parts 25 of the recess 22.

I claim: 1. Method of producing bags, envelopes or the like of paper and the like material, consisting in feeding the material to severing means but weak ening the width of the sheet material appropriate to one side 'of the ultimate bags before entering the severing stage, and then severing the remainder of the width of the sheet material by .the severing means, and substantially'contemporaneously with the severing operationtensioning the tubular sheet material suflicient to break the weakened side of the tubular sheet material along the perforated or weakened line.

2. Method of producing bags, envelopes'or the like of paper and like material, consisting in feeding the material to severing means, but weakening the material transversely for a portion of its width before severing it, folding the sheet material into tubular form so that the transverse weakening occupies one side of the tubular material and then severing the material at its other side substantially contemporaneously with applying tension to the tubular material to break it across a transverse weakening.

3. Method of producing bags, envelopes or the like of paper and like material, consisting in feeding the material in fiat tubular form to severing means but weakening one side of the flat tube before entering the severing stage, and then severing the material at its other side substantially contemporaneously with applying tension to the tubular material to break it across a transverse weakening.

4. Ina machine for manufacturingpaper and like bags, envelop'es or the like from tubular sheet material, a perforating device adapted to perforate the sheet material at intervals substantially transversely for a distance equal to approximately the width of the tube when flattened before the tube reaches the breaking or cutting stage, a cutting device located to sever only the imperforated side of the tubular sheet material,

means to subject the tubular sheet material to 'momentary pressure substantially along each line of perforations in juxtaposition to the effeclike bags, envelopes or the like from tubular sheet material, a perforating device adapted to perforate the sheetmaterial at intervals substantially transversely for a distance equal to approximately the width of the tube when flattened before the tube reaches the breaking or cutting stage, a cutting device located to sever only the imperforated side of the tubular sheet material, a presser bar adapted to move towards and enposite to that engaged byli e cutting device and substantially simultaneously with the cutting opgage the side of the tubular sheet material operation to subjectthe tubular sheet material to momentary pressure substantially along each line of perforations in juxtaposition to the effective operating zone of the cutting device, and means applying a momentary increase in tension on the material across the severing zone during the severing operation. a

6. Machine according to claim 4 wherein the perforating device comprises a pair of toothed 1 blades spaced laterally and each having a 1ongitudinal dimension approximately equal to one quarter of the width of the unfolded sheet material.

'7. Machine according to claim 4 wherein the perforating device comprises a pair of toothed blades spaced laterally and each having a longitudinal dimension approximately equal to one quarter'of the width of the unfolded sheet material, each blade being detachably held between abutments shaped to impart a bend to one end of each blade.

GORDON WILLIAM FRENCH. 

